X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Frcupdate.c;h=3554b76da84cf08ebc2808b5f2a237a362e52330;hb=6df95fd7ad9a842c1688d2b83bdcb7c82e9c8630;hp=6df1559b1c02bf33990ddd99294e0dbdc924ab5b;hpb=2178426d26661ed6e18a8d6ea0bc05c98d73600d;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 6df1559..3554b76 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -53,13 +53,13 @@
 static struct rcu_ctrlblk rcu_ctrlblk = {
 	.cur = -300,
 	.completed = -300,
-	.lock = SPIN_LOCK_UNLOCKED,
+	.lock = __SPIN_LOCK_UNLOCKED(&rcu_ctrlblk.lock),
 	.cpumask = CPU_MASK_NONE,
 };
 static struct rcu_ctrlblk rcu_bh_ctrlblk = {
 	.cur = -300,
 	.completed = -300,
-	.lock = SPIN_LOCK_UNLOCKED,
+	.lock = __SPIN_LOCK_UNLOCKED(&rcu_bh_ctrlblk.lock),
 	.cpumask = CPU_MASK_NONE,
 };
 
@@ -71,9 +71,6 @@ static DEFINE_PER_CPU(struct tasklet_struct, rcu_tasklet) = {NULL};
 static int blimit = 10;
 static int qhimark = 10000;
 static int qlowmark = 100;
-#ifdef CONFIG_SMP
-static int rsinterval = 1000;
-#endif
 
 static atomic_t rcu_barrier_cpu_count;
 static DEFINE_MUTEX(rcu_barrier_mutex);
@@ -86,8 +83,8 @@ static void force_quiescent_state(struct rcu_data *rdp,
 	int cpu;
 	cpumask_t cpumask;
 	set_need_resched();
-	if (unlikely(rdp->qlen - rdp->last_rs_qlen > rsinterval)) {
-		rdp->last_rs_qlen = rdp->qlen;
+	if (unlikely(!rcp->signaled)) {
+		rcp->signaled = 1;
 		/*
 		 * Don't send IPI to itself. With irqs disabled,
 		 * rdp->cpu is the current cpu.
@@ -182,6 +179,15 @@ long rcu_batches_completed(void)
 	return rcu_ctrlblk.completed;
 }
 
+/*
+ * Return the number of RCU batches processed thus far.  Useful
+ * for debug and statistics.
+ */
+long rcu_batches_completed_bh(void)
+{
+	return rcu_bh_ctrlblk.completed;
+}
+
 static void rcu_barrier_callback(struct rcu_head *notused)
 {
 	if (atomic_dec_and_test(&rcu_barrier_cpu_count))
@@ -229,15 +235,21 @@ static void rcu_do_batch(struct rcu_data *rdp)
 
 	list = rdp->donelist;
 	while (list) {
-		next = rdp->donelist = list->next;
+		next = list->next;
+		prefetch(next);
 		list->func(list);
 		list = next;
-		rdp->qlen--;
 		if (++count >= rdp->blimit)
 			break;
 	}
+	rdp->donelist = list;
+
+	local_irq_disable();
+	rdp->qlen -= count;
+	local_irq_enable();
 	if (rdp->blimit == INT_MAX && rdp->qlen <= qlowmark)
 		rdp->blimit = blimit;
+
 	if (!rdp->donelist)
 		rdp->donetail = &rdp->donelist;
 	else
@@ -288,6 +300,7 @@ static void rcu_start_batch(struct rcu_ctrlblk *rcp)
 		smp_mb();
 		cpus_andnot(rcp->cpumask, cpu_online_map, nohz_cpu_mask);
 
+		rcp->signaled = 0;
 	}
 }
 
@@ -416,8 +429,8 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp,
 		rdp->curtail = &rdp->curlist;
 	}
 
-	local_irq_disable();
 	if (rdp->nxtlist && !rdp->curlist) {
+		local_irq_disable();
 		rdp->curlist = rdp->nxtlist;
 		rdp->curtail = rdp->nxttail;
 		rdp->nxtlist = NULL;
@@ -442,9 +455,8 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp,
 			rcu_start_batch(rcp);
 			spin_unlock(&rcp->lock);
 		}
-	} else {
-		local_irq_enable();
 	}
+
 	rcu_check_quiescent_state(rcp, rdp);
 	if (rdp->donelist)
 		rcu_do_batch(rdp);
@@ -480,12 +492,31 @@ static int __rcu_pending(struct rcu_ctrlblk *rcp, struct rcu_data *rdp)
 	return 0;
 }
 
+/*
+ * Check to see if there is any immediate RCU-related work to be done
+ * by the current CPU, returning 1 if so.  This function is part of the
+ * RCU implementation; it is -not- an exported member of the RCU API.
+ */
 int rcu_pending(int cpu)
 {
 	return __rcu_pending(&rcu_ctrlblk, &per_cpu(rcu_data, cpu)) ||
 		__rcu_pending(&rcu_bh_ctrlblk, &per_cpu(rcu_bh_data, cpu));
 }
 
+/*
+ * Check to see if any future RCU-related work will need to be done
+ * by the current CPU, even if none need be done immediately, returning
+ * 1 if so.  This function is part of the RCU implementation; it is -not-
+ * an exported member of the RCU API.
+ */
+int rcu_needs_cpu(int cpu)
+{
+	struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
+	struct rcu_data *rdp_bh = &per_cpu(rcu_bh_data, cpu);
+
+	return (!!rdp->curlist || !!rdp_bh->curlist || rcu_pending(cpu));
+}
+
 void rcu_check_callbacks(int cpu, int user)
 {
 	if (user || 
@@ -521,7 +552,7 @@ static void __devinit rcu_online_cpu(int cpu)
 	tasklet_init(&per_cpu(rcu_tasklet, cpu), rcu_process_callbacks, 0UL);
 }
 
-static int __devinit rcu_cpu_notify(struct notifier_block *self, 
+static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
 				unsigned long action, void *hcpu)
 {
 	long cpu = (long)hcpu;
@@ -538,7 +569,7 @@ static int __devinit rcu_cpu_notify(struct notifier_block *self,
 	return NOTIFY_OK;
 }
 
-static struct notifier_block __devinitdata rcu_nb = {
+static struct notifier_block __cpuinitdata rcu_nb = {
 	.notifier_call	= rcu_cpu_notify,
 };
 
@@ -594,22 +625,11 @@ void synchronize_rcu(void)
 	wait_for_completion(&rcu.completion);
 }
 
-/*
- * Deprecated, use synchronize_rcu() or synchronize_sched() instead.
- */
-void synchronize_kernel(void)
-{
-	synchronize_rcu();
-}
-
 module_param(blimit, int, 0);
 module_param(qhimark, int, 0);
 module_param(qlowmark, int, 0);
-#ifdef CONFIG_SMP
-module_param(rsinterval, int, 0);
-#endif
 EXPORT_SYMBOL_GPL(rcu_batches_completed);
-EXPORT_SYMBOL_GPL_FUTURE(call_rcu);	/* WARNING: GPL-only in April 2006. */
-EXPORT_SYMBOL_GPL_FUTURE(call_rcu_bh);	/* WARNING: GPL-only in April 2006. */
+EXPORT_SYMBOL_GPL(rcu_batches_completed_bh);
+EXPORT_SYMBOL_GPL(call_rcu);
+EXPORT_SYMBOL_GPL(call_rcu_bh);
 EXPORT_SYMBOL_GPL(synchronize_rcu);
-EXPORT_SYMBOL_GPL_FUTURE(synchronize_kernel); /* WARNING: GPL-only in April 2006. */